Improved process of converting cast-iron into steel and malleable iron



FLETCHER & BLANCHARD.

Refining lron.

Patented Aug. 6, 1867.

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UNITED STATES PATENT OFFICE.

FRIEND I. FLETCHER AND VIRGIL XV. BLANCHARD, OF BEIDPORT, VT.

IMPROVED PROCESS 0F CONVERTING CAST-IRON INTO STEEL AND MALLEABLE IRON.

Specification forming part of Letters Patent No. 67,1126, dated AugustG, ISG?.

To all whom. it' may concern Bc it known that we, FRIEND P. FLETCHER andVIRGIL W. BLANCHARD, of Bridport, State of Vermont, have discoveredcertain new and useful Improvements in the Method of Converting Ironinto Steel; and we declare the following to be a full, true, and exactdescription of the same, reference being had to the accompanyingdrawings, and to the letters of reference marked thereon.

Figure l is a perspective view of our invention.

Letter A represents the furnace, in which the iron ore is meltedpreparatory to being converted into steel or malleable iron. Leadingfrom the hearth of this furnace is the trough B, through which themelted ore passes to the bath D. This trough is provided with a gate,(l, for the purpose of regulating the surplus metal. At the end of thetrough there is a second gate, so as to control the iiow of metal intothe bath and to prevent the ames from coming out. Leading off from themain channel E, just above the gate C, there is a second trough, E,which is much shallower than the large one. The molten metal pours fromthe hearth of the furnace A into the .main channel B, and flows down tothe gate, where, if the gate is closed, it will accumulate and run oft'through the shallow channel. E. In practice, this accumulation isallowed to take place, so that a sufficient stream will iiow throughthis channel to carry ofi' the scoria or slae. After the accumulation ofthe metal has taken place the gate is partly raised, when the heaviestpart flows under the gate into the bath, while the refuse or worthlesspart runs off through the channel E. These troughs should be slightlyinclined downward, so that when the stream of metal has been oncestarted it will be steady and continuous. Letter F represents anordinary steam-boiler, in which the steam to be used in our process isgenerated. Immediately under the boiler F is the receiver G. Thisreceiver is simply an air-chamber, which contains the `compressed airnecessary to give uniformity to the blast. Leading from both theair-chamber G and boiler F to the bath are two pipes H and I, which areprovided with suitable cock-stops, so that the currents ot' air andsteam, or the mixture of both, can

be regulated at pleasure. These pipes are made to pass through thesecondary furnace K on their way to the bath, where the steam or air, ora mixture of the two, can be heated toa degree approaching todecomposition before coming into contact with the stream of melted orein the bath. At a convenient dis tance above the secondary bath the airand steam pipes are connected to each other by a short pipe, which isprovided with a suitable valve, so that the air and steam can be mixedat pleasure. The waste heat of the furnacev may be so utilized as toimpart the required degree of heat to these pipes, and in that case isequivalent to this secondary furnace. Before these two pipes pass intothe bath they unite so as to form but one, and their contents can onlyescape into the bath through the small openings in the end of the troughB, over which the melted metal passes. Let ter D represents t-he bath,in which the melted ore is converted into steel or malleable iron. Thisbath may be constructed in the form as shown, or in any other one thatmay be convenient. Inside of the bath is placed the inclined plane L, asshown by red lilies, against which the metal is made to strike for thepurpose of more efectually reducing it to globules, atoms, or particles.As the stream of melted ore is started from the furnace a jet of steamor air, or a mixture ot the two, moving with greater or less velocity,is brought into contact with it inside of the bath. The force of thecurrent of air or steam, or a mixture of the two, reduces the moltenmetal to globules, particles, or atoms, while the heat of the samedecomposes the steam or air into gaseous elements, thereby bringing eachglobule, particle, or atom of the melted metal into contact with it.Oxygen, 11ydro gen, or any other gaseous element, or any mixture ofgaseous or volatile elements, may be used instead of steam, air, or themixture of the two, according to the impurities required to beeliminated from the melted metal. IVe do not restrict ourselves to theuse of steam or air, but claim the use of any gaseous or volatileelement that the nature of the metal may require to effect the desiredconversion or transformation. It will be particularly observed that itis by globularizing or atomizing the melted ore that a homogeneousproduct is obtained. By reducing themetal to globules or atoms the wholemass is brought into immediate contact with the gaseous elementscontained within-the bath, and it is by this process onlyl thathomogeneity is obtained. By means ofthe gate in the trough, leading fromthe hearth of the furnace to the bath, and the stop-cocks in the pipesleading throughthe secondary furnace, the size of the stream of meltedore, and the volume of the jet of steam or air, or a mixture of the two,may be regulated at pleasure. Thus, not only the amount ot' metal in thebath may be regulated, but the volume of gaseous element in the same, bymeans of which the elimination of the ilnpurities contained in the metaltakes place.

l Hence, by increasing or diminishing the size ot' the stream of meltedmetal with a given volume to the jet of gaseous element or elements, orwith a given size to the jet of gaseous elements, with a variable volumeof melted metal, a greater or a less proportion of sulphur, phosphorus,or any other impurity in the metal for which a gaseous element withinthe bath may have achemical affinity, may be removed from the moltenmetal at pleasure. As the ore flows into the bath it is thrown againstthe inclined plane by the force of the j et, and becomes reduced toatoms or particles, which are reilected through the gaseous elementcontained in the bath. In the journey which the atoms take through thegaseous elements, coming in free and immediate contact with it, theimpurities which the metal contains are eliminated or driven oli' bychemical affinity, leaving malleable iron. By

means of the pipe M, which is connected withV the other two, H and I, asecondary jet or jets of air, steam, or a mixture of the two, isintroduced into the molted iron after it has been globularized. Theforce of this jet or jets, aided by the sudden expansion of the gaseouselements contained in the jets, consequent upon the intense heat ofmolten iron, completes the globularizing and atomizing of the ore. Assoon as this process is accomplished the ore is then run out through thechannel N into railroad-rails, gearing, or any other form del sired.Some ores requireair alone or steam alone to best effect the requiredconversion.

Te do not claim ebullition or boiling, but simply atomizing orglobularizing, as above described. Neither do we claim the injection ofthe gaseous element or elements into or through a stream of molten iron,allowing such stream to preserve its continuity as a stream.

Having thus described our invention, what we claim, and desire to secureby Letters Patent is- 17. We claim dispersin g or reducing the moltenmetal to an atomic condition in the presence ofthe gaseous element orelements contained in the bath, substantially as and for the purposespecified.

2. We claim the forcible dispersion of a stream of molten metal into aglobular or atomic condition when it comes in contact with a jet or jetsof a gaseous element or elements, substantially as and for the purposespecified.

3. We claim the introduction of a secondary jet or jets of a gaseouselement or elements into the bath above, below, or beyond the primaryone, substantially as and for the purpose specified.

4. We claim the use of an inclined plane, or its equivalent, within thebath, in combination with sai/d bath, as and for the purpose specified.

5. We claim a secondary furnace, or its equivalent, for the purpose ofheating the gaseous elements, substantially as and for the purposespecified. v

6. We vclaim a gate or valve in the main trough or channel, incombination with said trough and the shallow channel and bath,substantially as and for the purpose specified.

7. We claim the employment or use of the necessary valves in the pipesleading from the boiler and receiver to the bath, for the purpose ofregulating the flow of gaseous element or elements into said bath,substantially as and for the purpose speciiied.

8. "We claim the use of any gaseous element or elements besides thosecontained in air or steam, used and applied substantially as and for thepurpose specified.

In testimony that we claim the above as our own we hereby afix oursignatures in the presence of two witnesses.

Witnesses H. HALE, J. L. HAMMOND, N. S. BENNETT.

